Method for treating aqueous dispersions of rubber and products obtained thereby



Patented Mar. 18, 1930 UNITED STATES PATENT OFFICE" MER'WYN C. TEAGUE,OF JACKSON HEIGHTS, NEW YORK, ASSIGNOR TO THE NA'UGA- 'rucx CHEMICALCOMPANY,

CONNECTICUT or NAUGATUCK, commcrrcur, A; conrona'rron 01 METHOD FORTREATING AQUEOUS DISPERSION S 01 RUBBER AND BRODUCTS OBTAINED THEBEBY ii No Drawing.

.methodfor preparing stable mixtures of aqueous" dispersions of rubberand wood tars f and distillation products.

fluid compositions.

'It has not been hitherto possible to prepare stable compositions of.rubber dispersions and wood distillation products such asthe" cheapmaterials, such as leather. It may be acid tars for the reason that the.acidic, al.- coholic' and phenolic nature of the tars causescoagulation of the rubber dispersion. For this reason the adhesiveproperties of such materials as pine tars as well as their softeningeifect has not been utilized in adhesive compositions which consists inpart of aqueous dispersions of rubber. According to the presentinvention a method has been developed whereby such softeners withacidic, alcoholic or phenolic properties can be mixed with rubberdispersions, eitherartificial or natural to give stable compositionshaving desirable-adhesive properties.

The invention accordingly comprises a method for introducing wooddistillation products, particularly the acidic tars, into aqueous rubberdispersions to form stable The invention also has as one of its objectsan improved adhesive composition and method of making the same.

With the preferred embodiment in mind but without intention to limit theinvention beyond What may be required by the prior art, the inventionconsist'sin neutralizin the acidic wood distillation products with a"ase, mixing the neutralized product with another agent adapted toincrease the adhesive properties of a rubber dispersion, forming anemulsion of the mixture in the presence of an emulsifyingagent, andcombining the emulsion thus formed with an aqueous dispersion of rubber.v

In carrying out the invention, an acidic ligneous product such as pinetar is carefully neutralized with a base. 7 For this purpose a solutionof soda ash, sodium hydroxide or of ammonia may be employed. I Theneutralized tar may then be mixed with say anequal quantity of a neutralresin such as cumar or ara indene. 1n 9. non-solvent thereof, preferablywater, an emulsifying agent being employed. The

This mixture is then emulsified Application. filed October 28,1925.Serial No. 65,492.

emulsion'which is thus formed may then be mixed with an aqueousdispersion .of rubber which may or may not contain other ingredients.The composition so formed will be found to be quite stableover a periodof time. It is also adesirable adhesive, particularly suitable forapplying to fabrics, or other used as a shoe cement.

To illustrate the invention, 12 parts of acidic pine tar are carefullyneutralized with .22 parts of sodium hydroxide or an equivalent ofammonia; With the neutralized tar are mixed 12% parts of cumar resin.The mixture is warmed and emulsified in 17 parts of water containing1.25 parts of saponin or Karaya gum. The emulsion, comprisingapproximately .44 parts, is then mixed With 100 parts ofrubber as latex.This composition will be stable for at least two months, and thestability'range is considerably greaterthan is required for manufactur-1n purposes. a

v y neutralizing the acid tar and mixing it with another agent adaptedto dull its coagulating efiect without destroying the adhesiveproperties of the tar, a two-fold purpose may be accomplishedincombining a material which has coagulative properties with a rubberdispersion and'at the same time preparing an adhesive composition whosestickiness has been increased by the addition of the tar. Instead ofemploying the cumar resin above mentioned, a mineral oil such as spindleoil may be employed as the ingredient which is mixed with theneutralized tar. In-

stead of the tar, other wood distillation products such as turpentineand the like may be substituted. The mixture of neutralized tar andresin can be emulsified by any suitable method, and'the emulsifying acut maybe Karaya gum, glue, saponin, or ot er material.

Having thus described my invention, what I claim and desire to protectby Letters Patmixingan approximately neutral hydrocarbon containingmaterial therewith, emulsifying the mixture in a substantiallynonsolvent thereof, and combining said emulsion with aqueous dispersionsof rubber.

2. A met od'of forming stable compositions from acidic substantiallywater-insolu-, ble wooddistillation products and aqueous dispersions ofrubber which consists in neuo tralizing said distillation products,emulsifying a mixture of said neutralized product and a'neutral resinousmaterial, and combining the emulsion with an aqueous dispersion ofrubber. q 3. A method of forming stable compositions from pine tar andaqueous dispersions of rubber which consists in neutralizing the pinetar with a base, mixing the neutralized tar with a neutral resin,forming an emulsion of said mixture and adding the emulsion toan aqueousrubber dispersion.

4. A method of forming stable compositions from pinetar and aqueousdispersions of rubber which consists in neutralizing the pine tar withan alkali, mixing the neutralized tar with cumar. resin, emulsifyingsaid mixture in a substantially non-solvent thereof in the presence ofan emulsifying agent, and adding said emulsion to the aqueous rubberdispersion.

5. A method of forming adhesive compositions frompine tar and rubberlatex which consists in'" neutralizing the pine tar with ammonia, mixingcumar resin therewith,

' emulsifying the mixture in water containing Karaya gum, and adding theemulsion to the rubber latex. 3 1 Y Y, 6. A stable adhesive compositioncontaining an aqueous rubber dispersion and an memulsion comprisingequal parts of alkali neutralized pine tar and cumar resin.

7. A stable composition containing an aqueous rubber dispersion and anemulsion of neutralized pine tar and cumar resin.

' Signed at New York, county and State of New York,-this 20th day ofOctober, 1925.

J MERWYN C. TEAGUE.

